Handling with precision and care
April 1, 2013
by Shane Whitaker
Because many raw materials present a variety of operational issues, automated ingredient handling systems that assist in making bakers more proficient can be real game-changers.
“Whether that be through the control of ingredient temperatures, process air conditions, cleanability of equipment, ease of maintenance, or process and production controls, ingredient handling systems can assist in making bakeries more efficient,” said Jason Stricker, Shick, Kansas City, MO. “Each of these areas can lower overall operating costs throughout the facility.”
A well-thought-out ingredient system reduces operational errors and, therefore, wasted materials, noted Dominique Kull, manager, bakery supply systems, Buhler, Inc., Minneapolis. Product quality also is more stable using automated ingredient systems, and these systems may allow bakeries to decrease the amount of ingredients per batch, he added.
Automated ingredient handling systems result in greater precision in ingredient delivery. “This increase in accuracy can result in an overall reduction of ingredient usage over an extended period,” Mr. Stricker said. “An automated system also reduces the amount of bag handling and, thus, the potential for product waste due to spills in the material handling process.”
From recent experience, bakers certainly know that raw material costs can vary considerably with rapid fluctuations. Also, specialized flavors, extracts and vitamin additives carry high prices and warrant careful handling.
High-accuracy feeding equipment and specialized conveying transfer systems ensure the exact amount of ingredients — be they majors, minors or even micros — are delivered precisely to the process, observed Sharon Nowak, global business development manager, food and pharmaceuticals, K-Tron, Pitman, NJ. “It is imperative that the ingredient handling and dosing systems be extremely accurate with minimal losses and high yields,” she said.
To maximize uptime, automated delivery systems allow bakeries to make quick and easy changeovers for recipe control, which can be extremely beneficial when dealing with multi-ingredient recipes, Ms. Nowak added.
Command and control
The primary advances in ingredient handling systems continue to be in the area of controls. “Electronic scales on silos, hoppers, bulk bag unloaders and even bag dumps provide much better recipe control and inventory management information than old paper-based systems,” said Bill Kearns, vice-president of engineering at The Fred D. Pfening Co., Columbus, OH.
Automated tending and alarming with weighing and delivery systems can flag problems areas before they become serious. “Bench scales with HMI prompts and acknowledgements can dramatically reduce operator errors and improve quality,” he added.
To reduce waste, bakeries need to properly size the equipment and understand the products being handled. Two fundamental issues that Nathaniel Davis, applications engineer, Zeppelin Systems, Odessa, FL, encounters in proposals for automated ingredient handling systems are speed/line capacities and accuracy. “In the baking world, time is money,” he said. “The more batches that can be completed in less time equates to more product that can be sold.”
Yet, Mr. Davis pointed out, fast is not necessarily accurate. When working on a new system, he said bakers are more interested in how many batches it can be maximized to handle. To get higher throughput, the equipment has to increase in size to handle high rates, which, in turn, decreases accuracy and increases the likelihood of inconsistent batches or ingredient waste.
“Additionally, when considering accuracy, extra equipment is sometimes needed to be able to meet broad weighments,” Mr. Davis stated. “Usually, an easier middle ground is discovered through the design process where the intended batches per hour are optimized without placing undo strain, making the equipment overall more affordable and more efficient.”
Recently, he worked on a large-scale project for which the client relied on Zeppelin’s recommendations. Bakeries commonly approach Zeppelin with a set number of ingredients they wish to automate and the number of batches per hour they desire, but Mr. Davis said that they increasingly send all of their formulas and ask for suggestions.
One bakery supplied better than 60 formulas using more than 200 different ingredients that he had to analyze to determine which were good candidates for automation. “The bakery then determined the number of ingredients to automate after a recipe study was done. Then, timing was examined to determine what the system could handle at its worst case,” Mr. Davis explained. “Because a batch consisted of multiple transfers and multiple scaling points, timing had to be looked at with each worst-case recipe from each line being proposed.”
Well-designed ingredient handling systems assure bakers that their ingredients will be dosed in the proper weights, according to Russell Nadicksbernd, system sales for AZO Food, Memphis, TN. “This reduces waste because there are no bad batches,” he said. “A bad batch is lost time and money, so every bad batch eliminated is payback on the investment.”
Making ingredient systems modular and upgradable has its advantages. John Hunter, sales manager, bakery supply systems, Buhler, described a recent installation at a special product bakery. The challenge was to start small and simple with the possibility to expand the plant once production increased. “However, the system needed to have all capabilities for a full-size automated ingredient system,” he said.
More accurate load cells, faster scale readers and more powerful computers have led to greater control. “These advantages not only help to have a better accuracy on the scales but also to track data that can further improve efficiency,” Mr. Hunter said. “In addition, recipe-based control systems can be designed as an integral part of an ingredient handling system, improving process control and quality assurance.”
At another recent Buhler installation, the challenge was to have a fully integrated system capable of exchanging data with an enterprise resource planning (ERP) system to get all recipes and production schedules downloaded as well as to provide feedback of the production usages. “Such a system can only be realized with a very high level of automation. Every scale, manual or automated, needs to be connected to the control system and all these data need to be processed and stored,” Mr. Kull said. “The advantage of such a system is that your production becomes fully traceable.”
Tortillas continue to represent a growing sector in baking, and K-Tron recently provided a complete turnkey system for production and handling of corn flour at a tortilla plant. According to Ms. Nowak, the plant manager reported reduced labor costs since automating the corn flour process because the system allows remote monitoring and control of all equipment. The final products were more consistent, and overall, the plant increased production by some 20% over manual ingredient handling.
Automated ingredient handling systems help remove much of the activity that creates dust problems in plants. As Mr. Nadicksbernd pointed out, super sacks and automated weighing systems eliminate manual emptying of bags, which is often the source of dust. “Properly addressed dust mitigation produces simplified dust collection,” he said.
Today’s ingredient handling systems generally include more effectively designed filtration systems. “With the increased focus on reduction of combustible dust emissions, companies are opting to install filter units with reverse pulse jet or other self-cleaning mechanisms, where in the past they might have attempted to use static filters,” Mr. Stricker said.
Additionally, filter media available today are far more efficient than older-style woven polyester bags. Shick’s IQC (Insertable Quick Change) filters feature a spun-bonded polyester media with a PTFE coating. “This results in higher filtration efficiency along with excellent release characteristics,” Mr. Stricker said.
Vacuum conveyors avoid or minimize dust creation. If a line ruptures or a valve leaks, the conveyed material is sucked back into the system, not blown out to create dust.
Equally important is control over dust when dispensing ingredients at their use points. Aspiration concepts/systems offer dust control when discharging pre-weight batches of flour or ingredients into mixing bowls. Central dust collection systems address the need to control several points where dust is generated during discharges, according to Stephen Marquardt, sales director, Zeppelin. These points include bulk bag unloading/handling, mixer filling stations and filling of packaging lines. Most important is the explosion protection on filter stations.
Conversely, poorly designed aspiration systems may result in dust escaping from bins and receivers, causing hygiene issues, potential cross contamination as well as allergen issues and exposure of staff to dust. “Modern technologies that control and monitor the entire system provide operators with early indicators if any problem is coming up,” Mr. Hunter said.
Dust control must be integral with the equipment and not an afterthought. “Hoppers, bins and other vessels must be dust-tight wherever possible,” Mr. Kearns noted. “Access doors into normally sealed vessels must be equipped with good gaskets and reliable latches.”
Also, bag dumps, bulk bag unloaders and tote systems must have well-designed dust collection systems as part of their design.
Indoor flexible fabric silos from Contemar Silo Systems, Concord, ON, are constructed with material that covers the entire top of the silo and acts as a giant filter. “The flexible nature of this unique material and the fact that it is constantly moving during the filling and unloading process results in a self-cleaning filter that provide dust-free filling into the storage silo,” said Kevin Rohwer, the company’s vice-president.
When conveying from a storage silo to a receiving or scaling hopper, that hopper must also have a filter system to separate the conveying air from the product being conveyed. This filter must keep the bulk ingredient and any dust within the receiving hopper, Mr. Rohwer advised. When these hoppers discharge their contents into the bakery’s mixer, the potential for dust can arise.
He recommended installing a flexible connection between the scaling hopper and the mixer to avoid negative effects on the accuracy of the scaling hopper and to ensure elimination of any dust, he added.
A recent installation by Contemar included a 75,000-lb indoor flour silo and a 55,000-lb indoor sugar silo delivering these ingredients to a single receiving hopper located approximately 250 ft from the silos. The receiving hopper was designed to be used with removable mixing bowls. It featured an automatic dust control lid that allows the operators to bring a mixing bowl to the scale hopper and then lower the dust control lid onto the bowl. “This minimizes any dust from emptying the scaling hopper,” Mr. Rohwer said. “This system allows the bakery to feed a large number of mixing bowls with a single receiving hopper, which helps reduce the overall cost of the system.”
Having qualified personnel to operate and maintain the ingredient systems is probably the single biggest challenge, according to Mr. Kearns. By making equipment robust and equipped with easy-to-understand alarms and maintenance programs, he said, equipment manufacturers help to ensure systems are regularly maintained.
Through improved accuracy with greater controls, automated ingredient handling systems provide precision and care in material handling to make bakeries more efficient and profitable.